production of tool steels by electro-slag remelting (esr)

during solidification of tool steels, especially when casting large ingot sizes, segregations may develop, resulting in an inhomogeneous microstructure throughout the ingot section. remelting these ingots in an electrically heated slag and a uniform cooling rate in a water-cooled copper mould cleans the steel and makes it largely free fro..

studies of chemically modified poly(ethylene terephthalate) fibers by ft-ir photoacoustic spectroscopy and x-ray photoelectron spectroscopy

fourier transform infrared photoacoustic spectroscopy (ft-ir/pas) and x-ray photoelectron spectroscopy (xps) were used to determine the location of a copolymeric finish in poly(ethylene terephthalate) (pet) fibers. the xps studies showed that the copolymeric finish was deposited on the fiber surfaces. the ft-ir/pas data demonstrated possi..

membrane based sensors. a review

chemical sensing technologies impinge upon a range of scientific disciplines. there is an overwhelming need for simple detection and monitoring devices suitable for use by the non-specialist analyst, particularly in the field. this review outlines the basic principles of the major chemical and bio-sensing technologies. these include ion-s..

xps/sem characterization of surface-treated carbon fibres

chemical characterization of the carbon fiber (cf) is conveniently accomplished by coupling two of the most widely used techniques in the field of cf analysis: x-ray photoelectron spectroscopy (xps) and scanning electron microscopy (sem) preliminary results showed that cf are a special challenge to xps spectroscopists since the analysis i..

harvesting recombinant microbial cells using crossflow filtration

a contained, crossflow filtration (cff) membrane system is described for harvesting saccharomyces cerevisiae and escherichia coli cells. this system is portable and can be cleaned and sanitized in place. low-and high-cell density (lcd, hcd) fermentations of recombinant cells in 10- to 200-l volumes were used as the starting material. lcd ..

effect of polyamic acids on interfacial shear strength in carbon fibre/aromatic thermoplastics

carbon fiber surfaces were coated in various thickness with polyamic acids (paa) prepared from (1) benzophenone tetracarboxylic dianhydride (btda) and 4,4 $prime$ -diaminodiphenyl ether (oda), (2) btda and 4,4 $prime$ -diaminodiphenyl sulfone (das), and (3) btda and oda modified with bisaminopropyldisilane, designated as paa-1, paa-2 and ..

surface modification of polyolefins for hydrophilicity and bondability. ozonization and grafting hydrophilic monomers on ozonized polyolefins

ozonization is a very efficient, economical, and potentially practical method to modify polypropylene (pp) as well as polyethylene (pe) surfaces. carbonyl, carboxyl, and hydroperoxide groups can be very conveniently generated by reacting these polymers with ozone. in the case of fibers and powders, surface treatment with ozone in an aqueo..

influence of phthalic anhydride as a coupling agent on the mechanical behavior of wood fiber-polystyrene composites

the performance of phthalic anhydride used as a coupling agent in wood fiber-filled polystyrene composites have been verified by evaluating the mechanical properties of the composite materials generally, mechanical properties improved along with the increase in concentrations of the coupling agent as well as wood fiber in the composites u..

effect of some surface treatments on corrosion of stainless steel. a review

during fabrication, the surface of stainless steel wrought products undergoes major changes, including mechanical (e.g., gouges, grinding marks), iron contamination, effects due to welding, and general surface contamination. a literature review compares mechanical to chemical treatments. chemical surface treatments seem to be better than ..

enhancement in resolution and lack of radiation damage in a rapidly frozen iysozyme crystal subjected to high-intensity synchrotron radiation

x-ray data have been collected from a monoclinic hen egg-white lysozyme (hewl) crystal, rapidly frozen at 120 k on the end of a glass fiber, using high-intensity synchrotron x-radiation. a comparison of oscillation photographs taken at the beginning and end of data collection shows no evidence of radiation damage even though the crystal w..